Screen printing frames have had extensive use for many years. The typical frame is formed of wooden strips which are joined at their corners to form a rectangular frame of greater dimension than the area to be printed. A screen, usually a fine silk screen, which has been prepared for printing is placed over the frame and tacked in place while some manual stretching force is applied to the screen. When in use, the screen is at the bottom of the frame so as to rest on the material to be printed. The frame serves to confine the printing ink which is worked back and forth to force ink through the porous areas of the printing screen, then finally the screen and frame is removed for reuse. Usually, once the printing screen has been attached to a frame it remains attached and when not in use is stored in its frame.
It is often desired to do multiple color screen printing using several frames. For this purpose it is customary to provide reference marks on the set of printing screens, then attempt to register succeeding frames by appropriate stops on the printing table, or each frame is placed on a second metal frame and position for registering by set screws. After a run is completed each member of a set of printing frames must be stored in the two frames requiring increased storage space and added cost as these frames are not available for other use. While the outer frames may be removed, if an additional run is made, the tedious chore of re-registering the printing screens is required.